1. Technical Field
The present invention relates to a shutter assembly, particularly, to a shutter assembly for cameras and other optical apparatuses.
2. Related Art
Conventionally, for shutter assemblies, various techniques are known. For example, a shutter technique using two shutter blades has been proposed in Japanese Examined Patent Publication No. 45-35737.
Recently, cameras are required to be increasingly miniaturized, and all devices and components used therein must be miniaturized. Shutter assemblies are not an exception, and various proposals regarding miniaturization have been submitted. For example, a shutter technique using four shutter blades (sectors) to miniaturize a lens housing and a lens shutter has been proposed in Japanese Unexamined Patent Publication No. 54-135527. In this proposal, space efficiency, which is not sufficient with the aforementioned shutter technique using two shutter blades, is improved so as to contribute to miniaturization of cameras.
In designing small apparatuses such as cameras, however, only very small spaces can be provided, and in addition, members to be arranged therein must be changed over time. Therefore, the conventional techniques as described above are not sufficient depending on application requirements. For example, a problem arises in that shutter blades (sectors) operating in small spaces contact other members.
Also, when the number of shutter blades is increased, as in case of the shutter technique using four shutter blades, a problem arises in that light blocking ability for light leakage are apt to be impaired.